Solution -「洛谷 P3773」「CTSC 2017」吉夫特
DescriptionLink.求满足$$\prod _{i=2}^{k} \binom{a_{b_{i-1}}}{a_{b_i}} \mod 2 = \binom{a_{b_1}}{a_{b_...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.